how to produce a Silk/Satin material
You appear to be using glass shaders with high roughness to produce a satin-like effect. Glass shaders can cause a lot of noise and would not seem an ideal fit for cloth (which is essentially opaque). You might be able to get a suitable effect using the Velvet shader or something like the following :



The satin is effectively a diffuse material with an element of glossiness - but glossiness that behaves subtly different to a smooth flat surface. In addition, the reflection off the glossy surface has quite a high roughness with a hint of the 'base' color (since the 'shine' is a mix of diffuse from some fibres of the cloth and glossy from others - so the usual dielectric rule of uncolored reflction doesn't apply here) - hence the Mix node to allow the reflection color to be adjusted. The Fresnel with a high value allows the amount of 'shine' to be adjusted and the Power node adjusts how the glossiness varies based on angle.